Macroeconomic Effects From Government Purchases and Taxes *

For U.S. annual data that include WWII, the estimated multiplier for defense spending is 0.6-0.7 at the median unemployment rate. There is some evidence that this multiplier rises with the extent of economic slack and reaches 1.0 when the unemployment rate is around 12%. Multipliers for non-defense purchases cannot be reliably estimated from U.S. macroeconomic time series because of the lack of good instruments. Since the defense-spending multiplier is typically less than one, greater spending tends to crowd out other components of GDP. The largest effects are on private investment, but non-defense purchases and net exports tend also to fall. The response of private consumer expenditure differs insignificantly…